@inproceedings{irwin1967functors,
title={Functors whose domain is a category of morphisms},
author={Irwin S. Pressman},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203212278919037},
booktitle={Acta Mathematica},
volume={118},
number={1},
pages={223-249},
year={1967},
}